Printer for alphanumeric characters

ABSTRACT

A printer such as one operable in series on ordinary paper, for the sequential printing of a series of alphanumeric characters forming a printing line with each of the characters being reproduced as an assembly of dots in accordance with a fixed outline formed by the nodes of an orthogonal grid from ink which is thermofusible and electrically conducting and an electrical melting device which is selectively energized to melt the sections of the ink at the selected points in the selected character outline.

United States Patent [191 Bastard et a1. j

[4 Dec. 31, 1974 PRINTER FOR AlLlPll-lANUMERllC CHARACTERS Inventors: Gilbert Bastard, Onex, Geneva;

Michel Moulin, Lausanne, both of Switzerland Battelle Memorial Institute, Carouge/Geneve, Switzerland Filed: May 3, 1973 Appl. No.: 356,943

Assignee:

Foreign Application Priority Data May 31, 1972 Switzerland 8011/72 lU.S. Cl. 197/1 R, 346/76 R, 346/135 lint. Cl B4lj 3/44 Field of Search 197/1, 172; 101/93 C, 1;

References Cited UNITED STATES PATENTS Newman 346/76 R X 2,858,633 11/1958 Kane 346/76 R X 3,299,433 l/1967 Reis 346/76 X 3,419,886 12/1968 Ortlieb 346/76 X 3,442,699 5/1969 Dalton 346/135 X 3,596,055 7/1971 Elston 346/76 R X 3,744,611 7/1973 Montanari 197/1 R Primary ExaminerRobert E. Pulfrey Assistant ExaminerR. T. Rader Attorney, Agent, or Firml-lubbell, Cohen and Stiefel [57] ABSTRACT A printer such as one operable in series on ordinary paper, for the sequential printing of a series of alphanumeric characters forming a printing line with each of the characters being reproduced as an assembly of dots in accordance with a fixed outline formed by the nodes of an orthogonal grid from ink which is thermofusible andelectrically conducting and an electrical melting device which is selectively energized to melt the sections of the ink at the selected points in the selected character outline.

8 Claims, 12 Drawing Figures PRINTER FOR ALPHANUMERIC CHARACTERS The invention is concerned with a printer designed for the sequential printing of a series of alphanumeric characters forming a printing line, each of such characters being reproduced in the form of an assembly of dotted marks arranged in accordance with a fixed outline formed by the nodes of an orthogonal grid, the printer being composed of:

a printing support;

an ink support covered with a layer of thermofusible and electrically conducting ink;

a device for tightening and separating actuated in such a manner as to apply the ink support against the printing support and separate the two supports from each other;

a first displacement means actuated in such a manner as to move the tightening and separating device along the printing line;

a second displacement means actuated in such a manner as to move the printing support at right angles to the said printing line;

a selection device actuated in such a manner as to se lect the points of the outline corresponding to the character to be printed; and

an electrical melting device actuated in such a manner as to bring about the melting of the sections of ink situated in such selected points.

The term printer is used to refer to a writing machine that is not operated by the fingers ofa typist, but by electrical coded signals transmitted from another machine, such as an accounting machine or a computer, or a telecommunication unit.

Printers are divided into those that print character by character (printing in series) and those that print line by line (printing in parallel); another division is into those that work with ordinary paper and those that require a special paper. The printer forming the subject of the present invention operates in series on ordinary paper.

Printers of this type are already known, in particular those that are simple typewriters whose keyboard is either supplemented or entirely replaced by a device for the electrical operation of the characters. Yet such machines nevertheless make use of conventional striking actions for the transfer of ink to the printing support, so that their speed is limited by the inertia of the parts responsible for the striking; in addition, they are noisy, a feature that is increasingly evident when the printing speed is raised.

Other printers exist in which striking is carried out by means of a series of pins arranged in at least one column, the pins of a column being directed so as to strike selectively in function of the separation of the dots in the transverse section of the character to which such row of pins corresponds. The result is a printer that contains far fewer pieces to be selected and set in motion, this being an advantage. Yet printers of this type are still noisy and their speed is relatively slow due to the fact that the completion of a character necessitates the printing of several consecutive columns of dots.

Attempts have been made to minimise such difficulties by resort to phenomena other than the transfer of ink by percussion, in particular the burning of the printing support at various points along an outline reproducing the character required. For this purpose, use is made of a printing head that includes a mosaic of distinct active elements, whose entirety covers the position of a character. These elements may be either minute heating elements or minute sparking elements, according to whether burning of the printing support is obtained by localised heating or sparking. In either case, however, a special paper, that is to say a thermosensitive paper in the case of burning by heating or a metallised paper in the case of burning by sparking, must be employed. This disadvantage has led to the proposal of an entirely different type of process consisting of printing by means of a microjet of ink, whose trajectory is distributed by electrical deflection, in such a way that its end is shifted along a curve representing the outline of the characters, so that the impact of the jet on the printing support paper reproduces the outline. A machine of this kind combines the advantages of silence and rapidity. However, the direction system for the placing of the ink jet is as complicated as that of the scanning system of a cathode oscilloscope, which is a serious handicap. In addition, this machine uses a liquid ink, so that special precautions are required as far as tightness is concerned. Lastly, there is the danger of obstruction of the minute pipe producing the jet, so that various disadvantages arise.

The object of the present invention is a printer that works with ordinary paper and does not make use of percussion, yet is none the less simple, particularly with respect to the memorisation of the electrical signals generating the characters, with the result that its price is compatible with that of the small desk computers that are being produced at the present time. The characters are formed by a dotted outline, in which each dot is an element of a given rectangular matrix common to each.

The printer that is the object of the present invention is characterised by the fact that the electrical melting device includes: a group of m parallel tracks of electrodes, in being the number of dots forming the outline in the direction of its length, each of such tracks comprising a set of pairs of pointed electrodes, each of which is immersed in the said layer of ink and marks the border of such portion of ink, the pairs of electrodes of such group of tracks being aligned in accordance with transverse lines perpendicular to such tracks; a group of (m 1) parallel contact tracks, each of such tracks comprising a set of pointed contacts arranged in an uninked part of the ink support and parallel to the electrode tracks, the contacts of such group of tracks being aligned in accordance with lines perpendicular to such tracks, one electrode of each pair of electrodes of the same row being connected to the same contact of a corresponding transverse row of contacts, the other electrodes of each of the pairs of electrodes of this transverse row being connected one by one to the other contacts of the corresponding row, in such a way that the electrode tracks correspond one by one to the contact tracks, the additional contact track being common to all the electrode tracks; and (m 1) contact lines arranged on the lengthwise support in such a manner that each line faces a contact track, the contact lines being connected to the selection device.

The printer includes means for the application of the support for the contact lines against the ink support in such a way that the (m 1) contact lines are simultaneously in contact, one by one, with the contact lines of the corresponding track on the same transverse row.

The tightening and separating device includes at least one pressure roller encircled by the ink support in such a way that the latter forms a loop projecting towards the printing support, the axis of the roller being at right angles to the printing line in such a manner that the ink support touches the printing support while following a generatrix of the roller.

The first displacement means is actuated in such a way that: l when the tightening and separating device is shifted in the direction of the printing, the roller is made to turn on the ink support and the printing support, and: (2) when such device is shifted in the opposite direction, it keeps the roller apart from the printing support, keeps the contact support apart from the ink support, and entrains the ink support in a travel movement that replaces the used section of the ink layer with a virgin section of the same;

The selection device includes a synchronisation track formed of a set of reference groups kinematically integral with the ink support, each group being comprised of n references, where n is the number of dots in the outline in the direction of its length, a detection device being actuated in such a manner as to deliver electrical signals on the passage of these marks, the detection device being kinematically integral with the tightening and separating device in its lengthwise motion, and a generator of electrical pulses being actuated in such a way as to deliver to such of the contact lines as correspond to the points chosen by the selection device electrical pulses carrying enough current to bring about the melting of the section of ink, such generator being operated by the signals generated by the detection device.

The following description relates to a form of embodiment of the printer, given by way of example. The printer is illustrated in the attached drawings, wherein:

FIG. 1 is a plan view of the embodiment;

FIG. 2 is a section along line IIII of FIG. 1

FIGS. 3 and 4 are two sections along lines III-III and IVIV respectively of FIG. 1

FIG. 5 is a block diagram showing the printer assemy;

FIGS. 6 and 7 are a plan and section view respectively of a part visible in FIGS. 1 to 5;

FIG. 8 is an enlarged view of a part of FIG. 6;

FIGS. 9 and 10 are a plan and end-on view respectively of an alternative form of the printer;

FIG. 11 is an electrical diagram of the functional blocks shown in FIG. 5 and;

FIG. 12 reproduces a series of diagrams illustrating the operation of the main components of the diagram shown in FIG. 11.

As can be seen in FIGS. 1 to 4, the printer comprises a roller 1 constituting a means for the entrainment of a printing support, seen here in the form of a sheet of paper 2, designed to receive lines of printed characters having the dotted appearance displayed by the alphanumeric characters 3 in FIG. 3, arranged on a line 4.

The said printed characters are obtained from an ink support consisting of a ribbon 5 bearing an inked track 6 (FIG. 2) set both longitudinally and parallel to the axis 7, and covered with a layer of ink, such ink being simultaneously fusible and a conductor of electricity. The ribbon is made of an insulating material and also includes a contact track 8, which contains a number of electrodes 9 (FIG. 4), and a synchronisation track 10, bearing a set of marks arranged in groups of five. As can be seen in FIG. 8, where the structure of this synchronisation track is shown, the marks 11 are equidistant within eachgroup M,-"', such groups M," being separated from each other by a gap 1'. Each of such groups corresponds to a character and the five marks composing the same correspond to the five columns of dots forming the matrix within which each character is printed. The ribbon 5, whose structure is shown in detail in FIGS. 6 and 7, contains a plurality of electrical conductors, each of which has one end connected to one of the electrodes 9, while its other end is set at a point of the layer of ink covering the inked track. There is thus a bi-univocal electrical connection between each of such electrodes and a corresponding point of the layer of ink. The electrodes 9 are arranged both in lines parallel to the longitudinal axis 7 and in columns perpendicular to such axis. The ends of the conductors connected to the electrodes of the same column 12 are themselves arranged at points 13 of the inked track 6 and these also form a column perpendicular to the longitudinal axis 7, the column being situated in the continuation of column 12. In other words, the bi-univocal electrical connections that exist between the electrodes and the points of the ink layer relate to electrodes and inked points that are aligned along the same transverse line perpendicular to the longitudinal axis 7.

The ribbon 5 is guided between three guide rollers 15, 16, 17, mounted on a carriage 18, capable of moving along a guide 19 placed along the paper-holding roller 1 and parallel to the axis of the latter. The middle roller 16 is in a forward position with respect to the plane defined by the two side rollers l5, 17, with the result that the ribbon 5 is forced to project itself towards the paper-holding roller 1 and thus touch the paper 2 with its inked track 6 along a vertical line coinciding with the transverse line 13' defined by the column of electrodes 12 (invisible in FIG. 1, but in evidence in FIG. 4) that is coincident with the anterior generatrix of the centre roller 16. During the movement of the carriage 18, the ribbon remains still, so that the transverse line of contact l3moves gradually along the inked track 6 of the ribbon and along the line 4 of the printing support 2. This means that the inkcd part of the track that touches the latter is gradually and progressively renewed during the course of this movement.

In addition, the carriage 18 works together with a contact tape 20, this being also engaged by a group of three rollers 21, 22, 23 referred to as auxiliary guide rollers, of which the middle roller 22 is in a rearward position with respect to the plane defined by the two side rollers 21, 23, with the result that the contact tape 20 is forced to project itself towards the contact track of the ink supporting ribbon 5. This group of auxiliary rollers is mounted on an auxiliary carriage 24, which is engaged by a groove 25 provided on the main carriage The contact tape 20 is composed of a substrate in flexible, synthetic, insulating material, on which are traced as many contact lines 26 as there are electrodes 9 in a column 12 of the contact track 8 of the ribbon 5. These lines of contact are set lengthwise and are formed of a conducting material laid on the surface of the substrate facing the ribbon 5. The contact tape 20 is fixed at its two ends to the frame 27 by means of insulating straps 28, 29 (FIG. 1) set at a height that will ensure that at the point where the tape 20 passes over the central roller 22 each line 26 will work together with a corresponding electrode of column 12 coinciding with the transverse line 13. The lines 26 are connected, at one of the ends of the contact tape, to a bundle of wires 30 to make a connection between such lines and the outlet 31 of a drive circuit 32 (see FIG. 5).

The part of the ribbon 5 bearing the synchronisation track engages with a groove 33 provided in the carriage 13, which is equipped with means (not shown) capable of revealing the passage of the marks ll and of engendering a signal corresponding to each of such passages. These electrical signals are routed by a wire 34 to the input 35 of the drive circuit 32, which includes a piloting circuit 45 responsible for their numbering. Such numbering relates to a measure of relative displacement of the carriage 18 in relation to the inkbearing ribbon 5. Since the marks lll are distributed in groups of five, each group corresponding to a character (see FIG. 8), and since the groups are separated by gaps i corresponding to the gaps between characters, such numbering also defines the position of the character in the line. The groups M,'' are also distributed in series L", U corresponding to whole lines, and such series are separated from each other by gaps J corresponding to the passage from one line to the next. The numbering of the marks 11 thus also serves as an indication of the position of the character within the text itself.

The mechanism (not shown) that moves the carriage 18 is so actuated that, when the carriage is moved forward in the direction of writing, as shown by the arrow 36, the ribbon does not move, whereas when the carriage is brought back to return it to the beginning of the line, the mechanism simultaneously shifts the ribbon 5, though leaving the latter motionless with respect to the carriage. For this purpose, the entrainment mechanism is actuated in such a way as to shift the roller 16 away from the printing support 2 during the return movement of the carriage 2, to prevent the inked track 6 from rubbing on the same, and, at the same time, in such a way as to shift the auxiliary guide roller 22 away from the roller 16 to prevent the electrodes 9 of the contact track 8 from rubbing on the lines 26 of the contact tape 20. This arrangement therefore ensures that the section of inked track is renewed for each line of writing. ln other words, each character of a line is printed by a different piece of a section of the inked track 6, this being ensured by the fact that, during the movement of the carriage in the direction of the writing, the ribbon 5 turns on roller 16, and each line is printed by a different section of the same inked track, the replacement of a used section by a virgin section being brought about by the entrainment of the ribbon 5 during the return of the carriage.

During this return movement, the printing support 2 is shifted for the distance required to bring about the replacement of the line that has just been printed with a new line. This is achieved by employing a known means, for example by making the roller 1 turn once about its own axis 1 through an angle corresponding to one line feed, or by using some quite different external means capable of shifting the printing support 2 to the same extent.

The printer assembly is represented schematically in the functional block diagram in FIG. 5. Note may be taken of the paper-holding system 40 (including, in particular, as far as the parts already mentioned are concerned, the roller 1, printing support paper 2 and frame 27), the carriage l8 and its guide 19, the ink ribbon 5, and contact tape 20 and its mounting straps 28 and 29. Block 41 represents the mechanism governing the shifting of the carriage l8 along its guide 19, whereas block 42 represents the mechanism governing the shifting of the paper 2 for the line feed; block 43 represents the device that detects the marks carried by the synchronisation track 10 of the ribbon 5; block 32 represents the drive circuit, which includes a character generation circuit 44 and a piloting circuit 45, which, as will be seen later, is designed to govern the various operations in function of the signals issued by the detector 43, such signals being routed to it by line 34. Mechanism 41, which entrains the carriage 18, is associated with a device 46 that carries out four functions during the return of the carriage 18, namely: the mutual displacement of roller 16 and the printing support 2; the mutual displacement of roller 22 and roller 16; the engagement of the ribbon entrainment device; the engagement of the mechanism 42 used to feed the paper. The ribbon entrainment device includes a motor 47 that actuates a take-up reel 48, on which the used portion of the ribbon 5 is wound, the virgin portion of such ribbon being stored on a feeder spool 49. The four operations carried out by the device 46 are shown schematically by means of the broken lines 51, 52, 53 and 54 respectively.'Device 46 is governed by the drive circuit 32, to which it is connected by means of a line 50.

The assembly thus displayed in schematic form functions in the following manner. The carriage 18 moves from a position at the commencement of the line and is gradually moved to the right by mechanism 41; the various conducting lines of the contact tape 20 are energised at the moment when the first mark (mark m, in FIG. 8) is detected by the detector 43 in accordance with the successive combinations defined by the internal coded signals proceeding from the character generation circuit 44, which elaborates such signals as a function of external coded signals received via its input 55. These external coded signals determine the different characters of the sequence of alphanumeric characters that make up the line to be printed, whereas the internal coded signals represent the combination of dots obtained from the column by column analysis of each character. The elaboration of internal coded signals as a function of external coded signals is the result of transcoding carried out by the character generation circuit 44. This transcoding is a known operation and consists of the analysis of each character in five columns of seven dots each in the character in five columns of seven dots each in the case of a character breakdown into 5 X 7 35 dots, since other forms of breakdown exist. The internal coded signals govern the energising of the various lines 26 of the contact tape 20 and, via these, the various electrodes 9 of the columns 12 of the contact track 8 of the ink-carrying ribbon 5 in contact with the tape 20. The result is that electrical currents are created in the conducting ink at the dots of the column 13 of inked dots that form a combination corresponding to the combination of energised lines of the assembly of lines 26 on the contact tape 20. At each point in such combination, the conducting ink is heated due to the effect of the electric current, becomes liquid and transfers itself to the printing support at the point where it is in contact with the inked track in accordance with the line 13. This transfer gives rise to the printing of a first column of dots corresponding to a character, after which the carriage 18 moves on over a distance corresponding to the gap between one column and the next of the same character, a new line combination 26 is energised by the character generation circuit 44 at the moment when the second mark (mark m in FIG. 8) is detected by the detector 43 and the next following column of dots is marked on the printing support 2. Five similar operations, corresponding to the detection of the five marks 111 to 211,-, of group M (FIG. 8) lead to the printing of the first character. This is followed by a feed movement corresponding to the gap i between groups M," and M after which the process is repeated for the printing of the second character, namely that corresponding to group M Further repetitions are carried out as a function of the sequence of signals (one per character) that the character generation circuit 44 receives through the input line 55. On each occasion, it is the position detector 43, via the piloting circuit 45, that governs the renewal of the combination of energised lines 26, such combination being determined by the character generation circuit 44. Once a complete line has been completed, the piloting circuit sends a signal on line 50 to disengage the fourfold action of the device 46 and, by reversing the travel of the mechanism 41, brings the carriage back to the start of the line.

During the return of the carriage 18, the reel 48 brings forward the ribbon 5 for the distance required to replace the section of inked track used for the printing of the last line with a virgin section and the mechanism 42 feeds the printing support 2 (FIG. 1) through the distance corresponding to one line feed. Printing of the next line can now be commenced.

The printer described above is designed to operate with an ink support ribbon 5 of the type mentioned, the structure of such ribbon being shown in FIGS. 6 and 7. It will be recalled that this consists of an insulating ribbon 60 bearing an inked track 6 composed of a layer of ink 61 laid lengthwise, the ends 62 of conductors 63 from electrodes 9 applied on a contact track 8 parallel to the inked track 6 being embedded in such layer. Both the electrodes 9 and the ends 62 of the corresponding conductors are arranged in rows 12 and 13 respectively, having a common axis 14 set perpendicularly to the longitudinal axis 7 of the ribbon 60.

However, the non-sliding contact brush forming the device composed ofthe contact tape and the rollers 21, 22 and 23 carried by the carriage 18 may be employed in association with other types of ink support ribbon. In this connection, it has been suggested that, in the printing of alphanumeric characters, use can be made of an inked ribbon formed of an insulating substrate crossed through from one side to the other by a plurality of conductor paths electrically connecting points of one of the surfaces of such ribbon to corresponding points on the other surface, one of such surfaces being covered with a layer of conducting and fusible ink forming an inked track. Printing is carried out by bringing the inked track of the ribbon into contact with the printing support and applying an electrical current between certain points of the uninked surface distributed along the trace to be reproduced, that is to say along a transverse line in the case of printing alphanumeric characters broken down into successive columns. In cases where the electrodes of the contact track are situated on the opposite surface of the ink support with respect to the inked track, use can be made of the non-sliding contact brush" described above if an alternative version of the printer is employed, such alternative being illustrated in its essentials in FIGS. 9 and 10. In these two drawings, the parts that are different with respect to the embodiment shown in FIGS. 1 to 4 are indicated with the same reference numbers. Since the conductors set up an electrical connection between the points of the inked track and those situated on the opposite side of the ribbon, it is necessary to arrange that the contact tape touches the uninked surface of the ribbon 5. To achieve this, the contact tape 20 is inserted between the middle roller 16 of the carriage 18 and the ribbon 5, the inked surface of the latter being in contact with the printing support, that is to say a sheet of paper 2. The two side rollers 21 and 23 that guide the contact tape 20 are set behind the side rollers 15 and 17 guiding the inked ribbon 5. As in the first embodiment, these side rollers 21 and 23 are mounted on the auxiliary carriage 24; this, by contrast, carries the middle roller 16 which is simultaneously associated with the ink support 5 and the contact tape 20; side rollers 15 and 17 are associated with the inked ribbon 5 only and, as in the first embodiment, are mounted directly on the main carriage 18. It can be seen that, inthis case, the middle roller 22 (FIGS. 1, 2, 3) which, in the first embodiment, forced the contact tape to project itself towards the inked ribbon 5, is eliminated, since its task is perforated by the middle roller 16, which compels the inked ribbon 5 to project itself towards the print support 2. With the exception of this modification, the printer is the same.

The drive circuit 32 is illustrated in FIG. 11. Its operation is shown in the drawings reproduced in FIG. 12. As can be seen, this circuit is composed of two essential parts, that is to say a character generation circuit 44 and a piloting circuit 45. The heart of the character generation circuit is a character generator 70, which receives signals representing different characters to be printed from the line 55. In FIG. 5, this line is shown schematically as a single line for the sake of simplicity only. In fact, it is a line consisting of six channels, such as that shown in FIG. 11. These six channels convey characters in digital form, in accordance with a known code, such as the USACII code. The character generator is an ordinary, commercially available component, for example the MOS integrated circuit component supplied by TEXAS INSTRUMENTS company, and described as TMS 4100 JC. It may be recalled that this component is used to analyse the character represented by the input signals applied to line 55 in a sequence of five configurations of seven bits each. The bits of these configurations appear on the seven output lines 71 and the passage from one configuration to the next is actuated by the energisation of the various selection lines 72. In other words, the character generator 70 carries out the analysis of the character represented by the signals appearing at the input 55 into five columns of seven dots each. The signals obtained by such analysis are amplified by an amplifier 73 and delivered to the seven channels that constitute the output line 31 of the character generation circuit 44. The successive energisation of the five selection lines 72 is ensured by a counter 74, which counts the pulses generated by the detector 43 responsible for reading the marks 11 carried by the synchronisation track 10 of the ink support ribbon 5 (FIG. 4). This counter is then connected to the line 35 coming from detector 43. This same line 35 also attaches a pulse discriminator 75,

which is actuated in such a way as to distinguish the passing of the gaps J (FIG. 8) separating lines L" and L" 1 and deliver a signal L showing the end of the line for each of such passages. This signal is routed on a bistable rocker 77, such rocker being in a condition that eliminates the current R applied at the drive inout 76 of the counter 74. At this point, the counter is locked. Signal L generated by the pulse discriminator 75 is equally applied to a non-locking rocker 79, which changes condition on the appearance of the said signal. This non-locking rocker has a time constant equal to the time T taken by the carriage 18 (FIG. 5) to return to the beginning of the line due to the effect of the entrainment mechanism 411. When this time T has elapsed, the non-locking rocker 79 returns to its start condition and delivers a stop signal A, which tilts another rocker, namely the bistable rocker 80. This movement cuts out an amplifier 81 and, by means of the line 58, energises the entrainment mechanism 41 of the carriages 18 (FIG. 5). This mechanism 41 is actuated in such a way as to automatically return the carriage 18 to the beginning of the line, after having first brought into action the device 46 responsible for shifting the ribbon 5 of the printing support and the contact tape (shown schematically by the broken lines 51 and 52 respectively), engaging the motor 47, which displaces the ribbon 5 through a distance equal to that of the length of one line, so as to replace the used section of the inked track with a virgin section (shown schematically by the. broken line 53), and actuating the device 42 that displaces the printing support through a distance corresponding to one line feed (shown schematically by the broken line 54). When the carriage 18 has returned to the end of the line, the printer is ready to bring about the printing of a new line, such operation beginning at the moment when an outside signal P is applied to the drive input 82. This signal P, which is supplied from outside and may be produced, for example, by a computer for which the printer is an output unit, causes the simultaneous tilting of the rockers 77 and 80. Tilting of the former re-establishes the current R and thus unlocks the counter 74; tilting of the second rocker brings about the supply of current to the amplifier 8i and starts off the carriage 18. The printing process for the new line L" 1 then takes place in the same way as already described for the previous line.

In order to ensure that the arrival via line 55 of signals C representing characters in succession is synchronised with the movement of the carriage, the counter 74 is equipped with an additional exit 83. A signal E, known as a character extraction" signal and designed to control the arrival of data on the lines 55, appears on this exit. In addition, a non-locking rocker 84 is fitted to determine the duration of the pulses delivered by the character generator 70. The current supplied to the ink and hence the size of the printed dots will depend on such duration.

FIG. l2 illustrates the series of operations required for the printing of a line in the form of a set of dia grams. Diagram 85 shows the signal P received by the drive input 82 (FIG. 5). As soon as this signal P appears, the mechanism for shifting the carriage 18 (FIG. 5) begins to move in the direction indicated by the arrow 36 (FIG. 5) and shown on the diagram as This is illustrated on diagram 86, where it can be seen that this movement of the carriage in direction lasts for the period T (indicated at the bottom of the drawing). This period corresponds to the time required for the printing of one line and is followed by the period T namely the time taken for the carriage return movement in direction the arrow 36 (FIG. 5). Diagram 87 illustrates the series of pulses resulting from the detectionof the marks ll (FIG. 8) on the synchronisation track It). In this diagram, time period 1,, corresponding to the end ofa line, can be seen. Diagram 88 shows the change in drive voltage R resulting in the operation of the counter 74 during the period T, "'.-Diagram 89 illustrates the extraction signals E that appear at the auxiliary exit 84 of the counter 74 (FIG. 12). The five diagrams 90 show the pulses that appear in succession on the live selection lines 72 (FIG. 12) as the marks on the synchroniszv tion track are read by the detector 43 (FIG. 5). Diagram 9]. shows an end-of-line signal L corresponding to the detection of section J and diagram 92 illustrates the change of condition of the non-locking rocker 79. Diagram 93 shows the stop signal A that the latter delivers at the moment when it returns to its previous condition, after the time period T has elapsed. This stop signal halts the action of the device for shifting the carriage 18 (FIG. 5) and stops the same at the beginning of the line. Lastly, diagram 94 shows the shifting of the ribbon 5 (FIG. 5) that takes place during the return movement carried out by the carriage 18 during such time period T 4 In the examples described above, the synchronisation marks ll are arranged on the link support itself. It will be clear, however, that this is a preferred embodiment and that such marks could equally be arranged on some other form of support, such as a disk, for example, that was entrained in a synchronised manner with the carriage 18. It is, in fact, sufficient for the support of the synchronisation marks to be kinematically integral with the ink support 5 and for the device for the detection of such marks to be kinematically integral with the carriage 18.

We claim:

1. A printer for the sequential printing of a series of alphanumeric characters forming a printing line, each of such characters being reproduced in the form of an assembly of dotted marks arranged in accordance with a fixed outline formed by the nodes of an orthogonal grid, the printer being composed of a printing support an ink support covered with a layer of thermofusible and electrically conducting ink;

a tightening and separating device actuatable in such a manner as to apply the ink support against the printing support and separate the two supports from each other;

a first displacement means actuatable in such a manner as to move the tightening and separating device along the printing line;

a second displacement means actuatable in such a manner as to move the printing support at right angles to the printing line;

a selection device actuatable in such a manner as to select the points of the outline corresponding to the character to be printed; and

an electrical melting device actuatable in such a manner as to bring about the melting of the sections of ink situated in such selected points, said electrical melting device comprising a group of In parallel opposite to that shown by tracks of electrodes, m being the number of dots forming the outline in the direction of its length, each of such tracks comprising pairs of pointed electrodes, each of which is immersed in a portion of the layer of ink and defines the boundaries of such portion of ink, the pairs of electrodes of each group of tracks being aligned in accordance with transverse lines perpendicular to such tracks; a group of (m +l) parallel contact tracks, each of such tracks comprising a set of pointed contacts arranged in an uninked part of the ink support and parallel to the electrode tracks, the contacts of such group of tracks being aligned in accordance with lines perpendicular to such tracks, one electrode of each pair of electrodes of the same row being connected to the same contact of a corresponding transverse row of contacts, the other electrodes of each of the pairs of electrodes of this transverse row being connected one by one to the other contact of the corresponding row in such a way that the electrode tracks correspond one by one to the contact tracks, the additional contact track being common to all the electrode tracks; and (m+l) contact lines arranged on a lengthwise support in such a manner that each line faces a contact track, the contact lines being connected to the selection device; said melting device further comprising means for the application of the support for the contact lines against the ink support in such a way that the (m-H) contact lines are simultaneously in contact, one by one, with the contact lines on the corresponding track on the same transverse row; said tightening separating device including at least one pressure roller encircled by the ink support in such a way that the ink support forms a loop projecting towards the printing support, the axis of the roller being at right angles to the printing line in such a manner that the ink support touches the printing support while following a generatrix of the roller; said first displacement means being actuatable in such a way that when the tightening and separating device is shifted in the direction of the printing, the roller is made to turn on the ink support and when the tightening and separating device is shifted in the opposite direction, it keeps the roller apart from the printing support, keeps the contact support apart from the ink support, and entrains the ink support in a travel movement that replaces the used section of the ink layer with a virgin section of the same; and the selection device includes a synchronization track formed of a set of reference groups kinematically integral with the ink support, each group being comprised ofn references, where n is the number of dots in the outline in the direction of its length, a detection device actuable in such a manner as to deliver electrical signals on the passage of these marks, the detection device being kinematically integral with the tightening and separating device in its lengthwise motion, and a generator of electrical pulses actuatable in such a way as to deliver to the contact lines which correspond to the points chosen by the selection device electrical pulses carrying enough current to bring about the melting of the section of ink, such generator being operated by the signals generated by the selection device.

2. Printer in accordance with claim 1, wherein the contact tracks are arranged on the same side of the ink support as the layer of ink.

3. Printer in accordance with claim 1, wherein the contact traces are arranged on the opposite side of the ink support with respect to the layer of ink.

4. Printer in accordance with claim 1, wherein the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device.

5. Printer in accordance with claim 1, wherein the contact tracks are arranged on the same side of the ink support as the layer of ink, the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device and the application means include a second pressure roller arranged parallel to the first roller and encircled by the flexible tape in such a manner that the flexible tape forms a loop projecting in the opposite direction to that of the loop formed by the ink support, the flexible tape touching the ink support along the common generatrix followed by the second roller in resting against the first, the tightening and separating device being actuatable in such a manner as to tighten the second roller against the first during the lengthwise shifting of the device in the direction of the printing and to separate the two rollers from each other during the shifting of the device in the opposite direction.

6. Printer in accordance with claim 1, wherein the contact tracks are arranged on the opposite side of the ink support with respect to the layer of ink, the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device and the pressure roller is encircled by the flexible tape, the flexible tape being arranged between the roller and the ink support, the tape forming a loop projecting in the same direction as the loop formed by the ink support, the tightening and separating device being actuatable in such a manner as to separate the flexible tape from the ink support during the longitudinal shifting of the device in the opposite direction to that of the printing.

7. Printer in accordance with claim 1, wherein the longitudinal shifting of the tightening and separating device takes place at a constant speed over the whole of the distance corresponding to the printing of such line.

8. Printer in accordance with claim 1, wherein the synchronisation track is arranged on the ink support parallel to the contact tracks of the ink support and the detector is arranged on the tightening and separating Dedication 3,857,470.Gilbert Bastard, Onex, Geneva; Michel Moulin, Lausanne, both of Switzerland. PRINTER FOR ALPHANUMERIC CHARACTERS. Patent dated Dec. 31, 1974. Dedication filed Mar. 26, 1984, by the assignee, Battelle Memorial Institute.

Hereby dedicates to the People of the United States the entire remaining term of said patent.

[Official Gazette July 3, 1984.] 

1. A printer for the sequential printing of a series of alphanumeric characters forming a printing line, each of such characters being reproduced in the form of an assembly of dotted maRks arranged in accordance with a fixed outline formed by the nodes of an orthogonal grid, the printer being composed of a printing support an ink support covered with a layer of thermofusible and electrically conducting ink; a tightening and separating device actuatable in such a manner as to apply the ink support against the printing support and separate the two supports from each other; a first displacement means actuatable in such a manner as to move the tightening and separating device along the printing line; a second displacement means actuatable in such a manner as to move the printing support at right angles to the printing line; a selection device actuatable in such a manner as to select the points of the outline corresponding to the character to be printed; and an electrical melting device actuatable in such a manner as to bring about the melting of the sections of ink situated in such selected points, said electrical melting device comprising a group of m parallel tracks of electrodes, m being the number of dots forming the outline in the direction of its length, each of such tracks comprising pairs of pointed electrodes, each of which is immersed in a portion of the layer of ink and defines the boundaries of such portion of ink, the pairs of electrodes of each group of tracks being aligned in accordance with transverse lines perpendicular to such tracks; a group of (m +1) parallel contact tracks, each of such tracks comprising a set of pointed contacts arranged in an uninked part of the ink support and parallel to the electrode tracks, the contacts of such group of tracks being aligned in accordance with lines perpendicular to such tracks, one electrode of each pair of electrodes of the same row being connected to the same contact of a corresponding transverse row of contacts, the other electrodes of each of the pairs of electrodes of this transverse row being connected one by one to the other contact of the corresponding row in such a way that the electrode tracks correspond one by one to the contact tracks, the additional contact track being common to all the electrode tracks; and (m+1) contact lines arranged on a lengthwise support in such a manner that each line faces a contact track, the contact lines being connected to the selection device; said melting device further comprising means for the application of the support for the contact lines against the ink support in such a way that the (m+1) contact lines are simultaneously in contact, one by one, with the contact lines on the corresponding track on the same transverse row; said tightening separating device including at least one pressure roller encircled by the ink support in such a way that the ink support forms a loop projecting towards the printing support, the axis of the roller being at right angles to the printing line in such a manner that the ink support touches the printing support while following a generatrix of the roller; said first displacement means being actuatable in such a way that when the tightening and separating device is shifted in the direction of the printing, the roller is made to turn on the ink support and when the tightening and separating device is shifted in the opposite direction, it keeps the roller apart from the printing support, keeps the contact support apart from the ink support, and entrains the ink support in a travel movement that replaces the used section of the ink layer with a virgin section of the same; and the selection device includes a synchronization track formed of a set of reference groups kinematically integral with the ink support, each group being comprised of n references, where n is the number of dots in the outline in the direction of its length, a detection device actuable in such a manner as to deliver electrical signals on the passage of these marks, the detection device being kinematically integral with the tightening and separating device in its lengthwise mOtion, and a generator of electrical pulses actuatable in such a way as to deliver to the contact lines which correspond to the points chosen by the selection device electrical pulses carrying enough current to bring about the melting of the section of ink, such generator being operated by the signals generated by the selection device.
 2. Printer in accordance with claim 1, wherein the contact tracks are arranged on the same side of the ink support as the layer of ink.
 3. Printer in accordance with claim 1, wherein the contact traces are arranged on the opposite side of the ink support with respect to the layer of ink.
 4. Printer in accordance with claim 1, wherein the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device.
 5. Printer in accordance with claim 1, wherein the contact tracks are arranged on the same side of the ink support as the layer of ink, the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device and the application means include a second pressure roller arranged parallel to the first roller and encircled by the flexible tape in such a manner that the flexible tape forms a loop projecting in the opposite direction to that of the loop formed by the ink support, the flexible tape touching the ink support along the common generatrix followed by the second roller in resting against the first, the tightening and separating device being actuatable in such a manner as to tighten the second roller against the first during the lengthwise shifting of the device in the direction of the printing and to separate the two rollers from each other during the shifting of the device in the opposite direction.
 6. Printer in accordance with claim 1, wherein the contact tracks are arranged on the opposite side of the ink support with respect to the layer of ink, the support of the contact lines has the form of a flexible tape fixed motionless and parallel to the longitudinal trajectory described by the tightening and separating device and the pressure roller is encircled by the flexible tape, the flexible tape being arranged between the roller and the ink support, the tape forming a loop projecting in the same direction as the loop formed by the ink support, the tightening and separating device being actuatable in such a manner as to separate the flexible tape from the ink support during the longitudinal shifting of the device in the opposite direction to that of the printing.
 7. Printer in accordance with claim 1, wherein the longitudinal shifting of the tightening and separating device takes place at a constant speed over the whole of the distance corresponding to the printing of such line.
 8. Printer in accordance with claim 1, wherein the synchronisation track is arranged on the ink support parallel to the contact tracks of the ink support and the detector is arranged on the tightening and separating device. 